A reinforcing member for securing a large strength against a side collision is provided to a center pillar of a four-wheeled vehicle. The elongated-shaped reinforcing member, being a press-formed article made of a steel sheet, includes a three-dimensional shape having a raised portion which is raised in the middle of the width direction orthogonal to a longitudinal direction, as well as includes two flange portions extending outward in the width direction of the raised portion from raised portion base ends on both sides across the width in the raised portion. The hardening operations for strengthening partially the reinforcing member for the center pillar are disclosed below in patent documents 1, 2 and 3. Patent documents 2 and 3 disclose that both hardening regions to be hardened by quenching after heating and non-hardening regions not to be hardened are defined to extend in a longitudinal direction of the elongated-shaped reinforcing member for the center pillar, and the hardening regions and non-hardening regions are provided side by side in the width direction orthogonal to the longitudinal direction.
Though the reinforcing member of the center pillar is clamped by a clamping device at the time of a hardening operation, the clamping device shown in patent document 2 is the device holding tightly plural places in the longitudinal direction of the reinforcing member for the center pillar in a state of fixed position at respective flange portions as being the non-hardening regions.
Patent document 1: Japanese Patent Application Laid-open No. Hei10-17933 (paragraph number 0042, FIG. 4
Patent document 2: Japanese Patent Application Laid-open No. 2000-256733 (abstract, paragraph number 0037˜0040, 0044, 0045, FIGS. 1˜3)
Patent document 3: Japanese Patent Application Laid-open No. 2003-160062 (abstract, FIG. 4, FIG. 8)